Cutting tools for the trimming of sealed packaging-tube ends are used in tube filling machines where the tubes are processed in an in-line procedure; i.e., empty tubes provided with a closure are set into a holder in the machine, the tubes are indexed to a filling station where the tubes are filled with product through their open ends and then closed in order to be finally fed out in the form of filled tubes.
Apart from these process steps, there are normally additional steps in the form of checking operations, marking stations and trimming (i.e., clean-cutting) of the seal which provides the closed end after filling.
Present machines operate at a high production speed, which requires precision in the various processing stations.
It has been shown that certain tube materials, typically those in laminate form, comprise layers which cause a great deal of wear on the cutting tools or the cutting edges. This wear is possibly due to the presence of silicon oxide in the material.
An object of the present invention is to allow self-adjustment of the cutting tool while at the same time maintaining precision, as well as allowing readjustment as soon as the self-adjustment is no longer sufficient.
In British Patent No. 2,248,577 there is disclosed a cutter which is designed particularly for cutting paper in fax machines. Primarily, the cutter provides adjustment means for positioning an active blade and a passive blade such that the effective distance between the cutting edges of the blades is not too long. By using a resilient support for the passive blade, the cutter blades initially are set to overlap.